Playing sound notifications using Javascript?

Use this plugin: https://github.com/admsev/jquery-play-sound

$.playSound('http://example.org/sound.mp3');

Found something like that:

//javascript:
function playSound( url ){   
  document.getElementById("sound").innerHTML="<embed src='"+url+"' hidden=true autostart=true loop=false>";
} 

JavaScript Sound Manager:

http://www.schillmania.com/projects/soundmanager2/

$('a').click(function(){
    $('embed').remove();
    $('body').append('<embed src="/path/to/your/sound.wav" autostart="true" hidden="true" loop="false">');
});

First things first, i'd not like that as a user.

The best way to do is probably using a small flash applet that plays your sound in the background.

Also answered here: Cross-platform, cross-browser way to play sound from Javascript?